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-   -   Transmission shifts hard sometimes (

joe_shire 03-23-2010 03:46 PM

Transmission shifts hard sometimes
I have a 2000 pontiac bonneville ssei and sometimes whenever I am driving it it shifts hard but most of the time it shifts smoothly. Is there something wrong with my transmission that it shifts hard sometimes? The transmission is an automatic.

Danthurs 03-23-2010 03:53 PM

Most likely a bad trans mount. Check them over. If the trans was bad I would expect it to happen all the time.

GunsOfNavarone 03-23-2010 07:25 PM

If it not the mounts look into converting to Dextron VI and installing a shift kit. 11 months ago I was convinced I needed to rebuild the trans, did the Dextron VI and the shift kit- and the trans is running better every day- 30k miles later.

Tom_Sawyer_Man 03-23-2010 08:30 PM

If it engages into D and R hard to it could be a vacuum problem. I had hard engagement into D and R also 1-2 shifts were pretty hard and 2-3 shifts a little harder than normal. after a brief look under hood I found vacuum line had been totally knocked off trans. Stuck it back on fine ever since.

sgp358 03-23-2010 10:55 PM

The 2000 Bonneville does not have a vacuum modulator. You may have a bad pressure control solenoid. Scan for codes and report back.

Tom_Sawyer_Man 03-24-2010 12:32 PM

Thanks for the info I'l have to remember that

Danthurs 03-24-2010 12:34 PM

Remember, not all transmission codes will set a SES light.

sgp358 03-24-2010 06:28 PM

Originally Posted by Danthurs (Post 1437818)
Remember, not all transmission codes will set a SES light.

Correct, especially P1811, which is a pressure control solenoid related code.

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